The present invention relates to an instrument for testing eyesight, and more particularly to a remote-controlled LCD sight-testing instrument which is remote-controlled to show different test patterns for testing the user's visual acuity, and to indicate test result by digital.
In the ophthalmologic department of a hospital or an eye clinic, there is provided a sight-testing chart and illuminated by a light source for testing eyesight. This sight-testing chart has a plurality of test patterns of different sizes marked on it. The test patterns show a respective gap in different directions. The eye patient is requested to point out the direction of the gap at the assigned test pattern. This eyesight testing method has drawbacks as outlined hereinafter.
1. Because the test patterns are aligned longitudinally as well as transversely, the directions of the gaps at the test patterns can easily be memorized after several tests.
2. This eyesight testing method must be performed under the guide of the examiner, i.e., the eye patient cannot make a test accurately by oneself.
3. Because the sight-testing chart is hung on the wall, it tends to be covered with dust and dirt.
4. Because a big number of test patterns of different sizes are aligned transversely as well as longitudinally on the front side of the sight-testing chart, the size of the sight-testing chart cannot be minimized without affecting test accuracy.